@inproceedings{Leeuwen:1974:PSR:800119.803908,
    Address = {New York, NY, USA},
    Author = {Leeuwen, Jan van},
    BookTitle = {Proceedings of the sixth annual ACM symposium on Theory of computing},
    Keywords = {vector addition systems and no pdf},
    Location = {Seattle, Washington, USA},
    Pages = {303--309},
    Publisher = {ACM},
    Series = {STOC '74},
    Title = {A partial solution to the reachability-problem for vector-addition systems},
    URL = {http://doi.acm.org/10.1145/800119.803908},
    Year = {1974},
    acmid = {803908},
    bdsk-url-1 = {http://doi.acm.org/10.1145/800119.803908},
    bdsk-url-2 = {http://dx.doi.org/10.1145/800119.803908},
    date-added = {2013-11-04 12:55:37 +0000},
    date-modified = {2013-11-04 12:56:34 +0000},
    numpages = {7},
    doi = {10.1145/800119.803908}
}

@inproceedings{Leeuwen:1974:PSR:800119.803908, Address = {New York, NY, USA}, Author = {Leeuwen, Jan van}, BookTitle = {Proceedings of the sixth annual ACM symposium on Theory of computing}, Keywords = {vector addition systems and no pdf}, Location = {Seattle, Washington, USA}, Pages = {303--309}, Publisher = {ACM}, Series = {STOC '74}, Title = {A partial solution to the reachability-problem for vector-addition systems}, URL = {http://doi.acm.org/10.1145/800119.803908}, Year = {1974}, acmid = {803908}, bdsk-url-1 = {http://doi.acm.org/10.1145/800119.803908}, bdsk-url-2 = {http://dx.doi.org/10.1145/800119.803908}, date-added = {2013-11-04 12:55:37 +0000}, date-modified = {2013-11-04 12:56:34 +0000}, numpages = {7}, doi = {10.1145/800119.803908} }